Hello, Since the last update, I was able to change the "ImportJxlGraphic" function so that it modifies the input Graphic into the correct format. After this new addition, I was able to manually verify that .jxl images could be dragged and dropped or copy-and-pasted into Calc and Writer documents, and that the images that appeared in the documents were visually identical to the ones that were inserted.
I also modified the various patchsets so that the Jenkins/CI tests could pass, and I was able to get my changes to pass on all the tested operating systems except Windows. Of course, it is important to verify that the image importing works not just visually, but numerically (by comparing the color or alpha values in the individual pixels between the original image and the imported image, for example). To this end, I've added some unit tests. The main functionality seems to work, so in the last few weeks I will make changes as needed for correctness and add some more automated tests. And of course I will attempt to get the Windows version to work. This is my latest patchset: https://gerrit.libreoffice.org/c/core/+/208999/1. Thank you, Jesus Solis
